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Chapter 18 Classification. Organization and naming systems based on morphology and genetics . Humans have a tendency to see commonalities and differences, clustering images by appearance. Aristotelian classification. Life. Plant. Animal. Herb Shrub Tree.
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Chapter 18Classification Organization and naming systems based on morphology and genetics Humans have a tendency to see commonalities and differences, clustering images by appearance.
Aristotelian classification Life Plant Animal Herb Shrub Tree Aristotle grouped organisms based on appearance and abilities.
Why Classify? • To study the diversity of life, biologists use a classification system to name organisms and group them in a logical manner. • To avoid the confusion caused by regional common names. Texas bluebonnet (Lupinus texensis )
Taxonomy • the science of classification • Uses Latin…descriptive, universal, “dead” language that never changes • Uses binomial nomenclature • Two word naming system of Genus & species = scientific name • Uses hierarchy of categories from general to specific
Common names • Many people refer to organisms by common names rather than scientific names. • Be careful that common names do not always reflect the biology of the organism. • Example: starfish are not “fish”
Comparing related animals • Lynx rufus, lynx • Panthera concolor, mountain lion • Lynx canadensis, bobcat • Which two are more related? How do you know? Lynx Bobcat Mountain lion
Dichotomous key: system to identify organisms and their scientific names • A key is made up of sets of numbered statements. • Each set deals with a single characteristic of an organism, such as leaf shape or arrangement.
Carolus Linnaeus (1707-1778) • Created a classification system with seven hierarchical levels • Kingdom • Phylum • Class • Order • Family • Genus • species
Human classification: Kingdom Animalia Phylum Chordata Class Mammalia Order Primates Family Hominidae Genus Homo species sapiens
Giant panda Abert squirrel Coral snake Grizzly bear Black bear Red fox KINGDOM Animalia Sea star PHYLUM Chordata CLASS Mammalia ORDER Carnivora FAMILY Ursidae GENUS Ursus SPECIES Ursus arctos
Kingdom…Phylum…Class…Order…Family… Genus species…(variety) or (breed)
Phylogeny • Studying the evolutionary history and relationshipsof organisms
Cladograms • Making a Family Tree • Represent evolutionary relationships, phylogeny, and not just physical appearances
Cladograms • Cladistics: a phylogenic study that assumes how groups of organisms diverged and evolved Allosaurus Velociraptor Archaeopteryx Sinornis Theropods Flight feathers; arms as long as legs 3-toed foot; wishbone Down feathers Feathers with shaft, veins, and barbs Light bones
Traditional classification vs. Cladograms Appendages Conical Shells Crustaceans Gastropod Crab Crab Limpet Limpet Barnacle Barnacle Molted exoskeleton Segmentation Tiny free-swimming larva CLASSIFICATION BASED ON VISIBLE SIMILARITIES CLADOGRAM BASED ON DERIVED CHARACTERS
Current six-kingdom classification • Archaebacteria: prokaryotic • Eubacteria: prokaryotic • Protists: eukaryotic • Fungi: eukaryotic • Plants: eukaryotic • Animals: eukaryotic
Modern classification systems include the three-domain system which includes the 6 kingdom system. • Just a few years ago, all bacteria and some protists were labeled Monera.
Three Domain System DOMAIN EUKARYA DOMAIN ARCHAEA DOMAIN BACTERIA Kingdoms Eubacteria Archaebacteria Protista Plantae Fungi Animalia
Key Characteristics of Domains and Kingdoms Classification of Living Things DOMAIN KINGDOM CELL TYPE CELL STRUCTURES NUMBER OF CELLS MODE OF NUTRITION EXAMPLES Bacteria Eubacteria Prokaryote Cell walls with peptidoglycan Unicellular Autotroph or heterotroph Streptococcus, Escherichia coli Archaea Archaebacteria Prokaryote Cell walls without peptidoglycan Unicellular Autotroph or heterotroph Methanogens, halophiles Protista Eukaryote Cell walls of cellulose in some; some have chloroplasts Most unicellular; some colonial; some multicellular Autotroph or heterotroph Amoeba, Paramecium, slime molds, giant kelp Fungi Eukaryote Cell walls of chitin Most multicellular; some unicellular Heterotroph Mushrooms, yeasts Eukarya Plantae Eukaryote Cell walls of cellulose; chloroplasts Multicellular Autotroph Mosses, ferns, flowering plants Animalia Eukaryote No cell walls or chloroplasts Multicellular Heterotroph Sponges, worms, insects, fishes, mammals
Pro Uni both Pro Uni both Eu most uni both Eu most multi hetero Eu multi auto Eu multi hetero
Archaebacteria overview • prokaryotic • Most live in extreme environments such as swamps, deep-ocean hydrothermal vents, and seawater evaporating ponds. • Most do not use oxygen to respire. • Examples: Thermophiles,Halophiles, Methanogens
Eubacteria overview • prokaryotic • very strong cell walls • a less complex genetic makeup than found in archaebacteria or eukaryotes • diverse habitat • Examples: Strep, Lacto-bacillus, E. coli
Protist overview • diverse species that share some characteristics. • eukaryote • lacks complex organ systems • lives in moist environments • diverse metabolism
Protozoans: animal-like protists • Heterotroph: consume organic matter • Unicellular • Examples: Amoeba, paramecia
Algae: plant-like protists • Autotroph: uses light to make sugars through photosynthesis • Lack roots, stems, and leaves • Examples: algae, kelp, sea-weed
Fungus-like protists • Decompose dead matter • Motility during some stage of life cycle • No chitin in cell walls • Examples: Slime-mold, powdery mildew
Fungi overview • Eukaryotic • Decomposes matter by absorbing materials • Multicellular or unicellular • Examples: bread mold, mushrooms, athletes foot, ring worm
Plant overview • Eukaryotic • Multicellular • Photosynthetic: produce oxygen • Immobile, sessile • Cell walls • Examples: fruit, ferns, mosses, trees, grasses
Animal overview • Eukaryotic • Multicellular • Mostly mobile • Lack cell walls • Diverse habitats • Examples: lions, tigers & bears, oh my!
Nutritional types Auto(photo) Hetero(absorb) Hetero(ingest) Plantae Fungi Animalia (Seaweeds) Multi Uni Protista Eu Pro Bacteria Evolution and the 6 Kingdoms
Pro Uni both Pro Uni both Eu most uni both Eu most multi hetero Eu multi auto Eu multi hetero
Classification systems video Click on image to play video.
Panthera leo? (1) Click on image to play video.
Panthera leo? (2) Click on image to play video.